Wetland location and captive breeding influence trans‐Mediterranean movements in the endangered Marbled Duck (Marmaronetta angustirostris)

Waterbirds distributed in semi‐arid and arid regions seem to have adapted their behaviour to the availability and seasonality of wetlands, increasing their mobility range. The Marbled Duck Marmaronetta angustirostris is a threatened waterbird that shows trans‐Mediterranean movements but these are poorly known. In a conservation effort, there are two captive‐breeding programmes in Spain. Each year captive‐bred individuals are released in two main sites: Doñana and surroundings (southwest Spain) and the southern wetlands of Alicante (southeast Spain). In 2018, a GPS/GSM tagging project was launched to monitor the species to facilitate an understanding of their movement patterns and to assess the effects of captive breeding on the adaptation of individuals to the wild. This study presents the first description of long‐distance movements between North Africa and Europe by Marbled Ducks. Of the 144 GPS‐tagged individuals, only 18 crossed into Africa, the majority were wild‐born ( n = 14) and only four were from the captive breeding programme, indicating a strong effect of origin on the likelihood of undertaking long‐distance movements. Our results showed that long‐distance movements were not restricted to the wintering season but also occurred during the breeding season, showing a clear temporal pattern between the two main release/tagging sites: individuals from the southwest crossed mainly in April, whereas those from the southeast did so mainly in October. Birds showed heterogeneous movements at the individual scale (cumulative daily distance moved ranged from 0.1 to 447 km/day). Marbled Ducks performed significantly longer daily displacements during their time in North Africa than those observed in Spain. These findings reveal the complexity and flexibility of movement strategies in this nomadic species and suggest that long‐distance movements are individual responses to environmental conditions and wetland availability. Furthermore, we discuss possible explanations for the observed differences in long‐distance movements between wild‐born and captive‐bred individuals. These insights into the seasonal patterns and origin‐related differences in long‐distance movements are crucial for informing more effective conservation strategies for this endangered species.